Endocrine Abstracts

Patients on thyroxine have lower psychological well-being than controls using the GHQ12 questionnaire, which gives patients a score between 0 (very happy and well) and 36 (profoundly exhausted and feeling worthless). Average GHQ was 11.39 in controls and 12.09 in patients optimised on thyroxine(P=0.028)¹. Liothyronine has a large and sustained placebo effect with the GHQ improving from 13.5 to 11.0 in the WATTS study². This placebo effect needs careful explaining to patients. A genetic reanalysis of the WATTS study suggested an association between one point mutation and response to liothyronine in the subset of patients with one particular allele³. Various websites wrongly interpret this and suggest that those patients with "the gene" (allele CC in the SNP rs225014 which was associated with a Thr92Ala mutation) would be tired unless they were given liothyronine, despite having normal plasma T3 levels. A trial of liothyronine for patients who are tired despite adequate thyroxine replacement is fraught with the placebo effect, and benefit is also seen with placebo when patients are blinded but not in open label studies. Further studies have found no linkage of this gene with tiredness, even in those who are particularly tired on levothyroxine and apparently responded to liothyronine⁴. Resolution of life events that may have occurred after patients started liothyronine makes patients associate liothyronine with improvement in quality of life. They are often taking other placebos such as Ashwaganda, Turmeric and Co-enzyme Q. Listening to their story, reassuring such patients, and monitoring thyroid function while slowly weaning liothyronine has been the most successful method. It is essential that any future studies of liothyronine are carefully planned and properly randomised and blinded to avoid all the biases of previous studies. Open label studies of liothyronine are misleading and should not be carried out.